Multi speed transmissions for heavy vehicles of the type used in agricultural and constructional applications have varied widely in design. Frequently, a torque divider is incorporated in such transmissions to provide a multiple power path thus to decrease overall weight and size requirements and to overcome some of the inefficiencies found in direct drive transmissions. A torque divider normally narrows the operating range of a conventional transmission, therefore coupling a torque divider with such a transmission can provide more efficient operation over a desired narrow operating range which may be required in agricultural or construction use. Combining a torque divider with a conventional transmission to accomplish an efficient multiple drive path through a transmission is the primary purpose of this invention.
Accordingly, this invention couples an epicyclic type torque divider, having an input member, an output member and a reaction member to a multi-speed bi-directional range section. In particular, the input member of the epicyclic torque divider is coupled with the input member of the multi-speed bi-directional range section while the reaction member of the epicyclic torque divider is coupled with the output member of the range section. Thus, output from the range section is provided at the output member of the epicyclic torque divider. This invention also incorporates a reversing planetary system, drivingly located between the engine and the torque divider system. Several unique features will result from this arrangement. First, the reduction ratio of the transmission may be simply changed by varying the size of the input, output and reaction members of the epicyclic torque divider, rather than a complete redesign of the range section to which it is coupled. This unique feature enables a single design for the transmission to cover a wide range of vehicles such as may be encountered in agricultural or construction type work. A second unique feature of this transmission is the positioning of the forward-reverse section, thereby providing a complete range of forward and reverse speeds through all mathematically possible gear ratios. This positioning of the forward-reverse planetary arrangement also provides a possible forward and reverse capability in a power takeoff shaft, the direction of rotation of which will follow the direction of rotation of the output shaft of the transmission.